The document discusses the Combination Anchorage Technique (CAT) in orthodontics. CAT combines elements of the Begg technique using light wires in the gingival bracket slot with the straight wire technique using more rigid wires in the horizontal slot. The summary is:
1. CAT aims to use light wires in the gingival slot early in treatment for tooth movement, then transition to more rigid straight wires later for precise finishing.
2. Bracket and wire designs have improved to reduce friction and increase control of tooth movement. Tandem and dual flex wires provide flexibility and rigidity where needed.
3. Treatment involves phases using different wire positions and mechanics to efficiently align, level, retract,
2. CONTENTS
Introduction
Advantages and Disadvantages of Begg’s V/S straight wire appliances.
Bracket design
Retention pins
Bracket and tube placement
Arch wires – Dual flex 1 &
Dual flex 2
Treatment
Treatment phases and Goals
Treatment considerations
Conclusions
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3. INTRODUCTION
What’s CAT ?
Combination anchorage technique: Begg technique in orthodontics
last since 5-6 decades. Where as straight wire technique has taken
over hand over this technique since last 3 decades. Where there are
both advantages and disadvantages.
Improvements like :
More effective treatment.
Reduced the problems with appliance adjustments and esthetics.
Improvement to the Bracket itself.
Archwires like
-Tandem wires
-Stabilizing the arch wires
-Dual flex wires
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4. So that, these materials have increased the movement capability
and anchorage control.
With all these changes, a technique of orthodontics
mechanic has evolved that is called as CAT.
CAT in its early structure was principally a four stage
Begg light wire system, the fourth stage being the straight wire
finally.
The concept was to use a light wire appliance system to establish
the early organization of the malocclusion and to finish the
treatment with more rigid and precise straight wire appliances.
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5. BEGG LIGHT WIRE APPLIANCES
Advantages
Light optimum force levels 60-90 gms.
Relatively continuous force application.
Minimal friction of wires in brackets and tubes.
Rapid alignment, leveling, rotation of anterior teeth.
Rapid over bite correction, chiefly by means of molar extrusion and incisor
intrusion.
Simultaneously crown tipping retraction of all anterior teeth.
Continuous paralleling of roots at extraction sites by auxillary springs.
Relatively continuous torquing of upper or occasionally lower incisors.
Extra Oral force unnecessary except with extreme anchorage problems.
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6. DISADVANTAGES
Difficulty in coordinating maxillary and mandibular arch form
and width.
Difficulty in obtaining bilateral symmetry.
Difficulty in obtaining control of increase molar and molar torque
without the use of auxiliaries.
Difficulty in stabilizing teeth during final artistic position.
Difficulty in bodily movements.
No tip and torque in the brackets.
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7. STRAIGHT WIRE APPLIANCES
Advantages
Precise control of premolar and molar torque.
Bilateral symmetry of bucco lingual inclinations readily attained.
Bilateral symmetry of arch form.
Use of straight wires with few or no bends.
Precise control of finalizing in both arches in all three planes.
Self limitation of movement and stabilization of teeth during final
detailing.
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8. Disadvantages
Increased force levels because of the wider bracket and small
inter
bracket distance.
Difficulty in obtaining rapid anterior alignment because of
angular relation of the bracket slot to malposed teeth.
Difficulties in obtaining prompt over bite correction
When sliding mechanics is used – additional anchorage is
possible.
Extra oral force is often required.
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12. IMPROVEMENTS IN BRACKET DESIGN
The original combination brackets was
Bulky
Weak
Unesthetically unattractive
Problems with pinning, rotations, slot closure and occlusal interferences
These problems were eliminated in new bracket design
•Improvement in bracket design course from ideas and suggestions from
experience with several brackets designed for combination treatment.
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13. CAT BRACKET DESIGN
Clinically excellent for both light wire and straight wire treatment.
Comfortable.
Esthetically pleasing to the patient.
0.22 x 0.35” gingival or ribbon arch slot.
0.018 x 0.025” or 0.022 x 0.028” straight wire slot.
Vertical slot is also incorporated into the bracket for use with up righting
and rotating springs, elastic, hooks, double arch wires.
Color coding dots are used to identify the brackets.
Maxillary brackets are – Red in colour
Mandibular brackets are – blue.
Color coding dots are placed distogingival aspect.
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14. MODIFICATION IN BRACKETS DESIGNS
Maxillary incisor brackets – varying degrees of torque
Maxillary canine torque has been reduced to 0 to reduce the
prominence of the canine roots on the labial plate.
The torque in the lower 1st premolar was 170
and for lower 2nd premolar
was 200
.
It has been charged to standard 190
for both.
Molar attachment have convertible double tubes
It facilitates extending the straight wire into round molar tubes.
Redesigned 2nd molar tubes have reduced occlusal interference on
short crowned 2nd molars.
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16. Molar tube offset 70
to facilitate proper rotation – when straight
continuous arch wire are used.
Bracket size and contour have reduced.
These changes have reduced lip irritation by sharp corners.
Gingival extension of pads have been reduced to make placement
more accurate and occlusal interference less likely.
Redesigned pin slot and bracket pad have simplified placement and
retention of pins.
So that phase I & II can now be completed with the same type of pin.
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17. MODIFICATION OF PINS IN CAT
Lock in used in the technique are
Phase I & II retention pin
Phase III retention pin
Tandun,, hook pin
By pass clamp
Special pins – Reduce friction during tipping movement of an arch wire in the
gingival slot.
•New auxiliary extension pins have been contoured for lip comfort and
modified to hold an elastomeric ring or an elastic.
•Stainless steel extension pins are recommended for use with surgical
fixation ligatures. They are strong and with stand the tension of these
ligatures.
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19. BRACKET AND TUBE PLACEMENT
BRACKET AND TUBE PLACEMENT
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20. BRACKET AND TUBE PLACEMENT
similar to that of straight wire appliances like edge wise slot parallel and at
the same level as the interproximal contact point of the teeth in normal
occlusion.
Molar tube can be banded or bonded.
Remaining brackets are bonded on the anterior and premolars keeping the
molar tube as glide line.
Molar tube placement
rectangular tube 3.5 mm from the molar cusp tip.
Other teeth are at the level
If maxillary molars are interfering in static of functional occlusion,
-position have to be altered.
Canines edge wise slot should be 4mm
Maxillary lateral incisors 3 mm from the incisal edge.
Non extraction case – mandibular I premolar – 4mm
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21. BONDING THE BRACKETS
Long axis of the brackets should be parallel to the long axis of the crown.
Centered mesio distally on the long axis of the crown.
Care should be taken each bonding pad is present firmly against the tooth
and centered in its proper position to facilitates rotation and torque.
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22. TREATMENT
Treatment is modified, so it reduces tipping.
Reduce labial root prominence.
Shorter or eliminate stage III.
Anchorage resistance can be established to hold the anterior teeth while
the molar are moved mesially.
Initial alignment and retraction of anterior teeth, correction of canines to
Class I, and bite opening are accompanied by using light wire mechanics
with the gingival slot.
Maintenance of bite opening, anterior and posterior root torquing and
axial alignment of teeth such as uprighting and paralleling can be done
by use of 2 Tandem arch wires i.e . One in the gingival slot and one in
the straight wire slit.
This technique involved the placement of a 0.18” round stainless steel
wire in the gingival slot.
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23. This wire has slight anchor bends to open the bite.
The other wire Niti tandem wire in the straight wire slot.
This is useful in upright and torque.
Tandem wires serves to eliminates any relapse because the intrusive
forces
created by the rigid steel base arch in the gingival sot overcomes the
extensive force of the flexible Niti wire seated in the edge wise slot.
Maximum anchorage resistance is established in the posterior segment by
the segmented tandem arch in the straight wire slot while the anterior teeth
or tipped distally in the gingival slot by means of intra arch or inter arch
elastics.
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24. ARCH WIRES IN THE COMBINATION ANCHORAGE
TECHNIQUES.
These is no loops like inter maxillary loops for bite, bite opening, alignment
and retraction.
DUAL FLEX ARCH WIRES
These wire are more flexible in one segment.
Rigid resistance in the others.
Designed by Dr. James L. Canon.
Small guage , flexible arch wires, produces light forces.
Useful in initial alignment of crowded, mal posed teeth.
Wire spanes at extraction sites are longer and more flexible.
Space closure with inter or intra maxillary traction and over bite correction
requires stability in the buccal segments.
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25. Dual Flex archwires with cast hook Alignment with dual flex archwires
(after 5 weeks of treatment)
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26. DUAL FLEX ARCH WIRE 1
Multi-ligament wire with round – 0.16” stainless steel in the posterior
segment and sound 0.016” NiTi (titinal) in the anterior segment.
Titinal : Nickel titanium alloy manufactured by (anterior pacific.) cast ball
books are provided at the junction of the two segments just mesial to the
cuspids.
The flexibility of the anterior segment greatly simplifies bracket engagement
in crowded anterior teeth, while the rigidity of the posterior segments
controls rotations prevent tipping from elastic traction and permits bite
opening bends to be made easily.
Useful in lingual appliances, where anterior inter bracket width is greatly
reduced.
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27. DUAL FLEX 2
Round 0.018” stainless steel in posterior segment on either side and
0.016” x 0.22” titinal in anterior segment from canine to canine.
S.S. wire seated in the gingival slot where the resistance is minimal.
0.016” x 0.022” light flexible rectangular wire in the edge wise slot in the
anteriors; so increasing anterior resistance and facilitate incisor control as
the posterior teeth are moved mesially in the gingival slot.
Dual flex 2 is designed specifically for use with a combination bracket
when retraction of anterior teeth to upright positions does not utilize all of
the extraction sites.
TREATMENT
Generally mechanics for combination bracket treatment are
undertaken in phases.
Phases designed to facilitate the use of light wire or straight wire
mechanics at specific times and specific reasons during treatment.
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28. PHASE I : EARLY ORGANIZATION
Over bite correction is accomplished by bite opening mechanics.
Class I canine and molar retraction are achieved, correct all rotations, close
anterior space, over correct all rotations and other mal-positions.
Treatment mechanics are done in the gingival slot with Dual flex I arch
wires.
Class II elastics are used with 2 ½ - 3 ounces of force.
LATE ORGANIZATION
Maintain what all have achieved in Phase I, and continued but the arch wire
replaced in the edge wire slots of the anterior brackets. This permits initial
leveling of the anterior teeth and canine in a mesial and distal direction and
begins to establish anterior resistance to minimize anterior retraction.
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30. PHASE II CONSOLIDATION
All the mechanics of Phase I (early and late) should be continued.
Final space closure in the posterior segments.
Dual flex 2 - arch wire is used.
Edge wise slot in anterior teeth
Gingival slot in posterior teeth
Class I or Class II elastics with 3 ounces of force.
PHASE III UPRIGHTING AND TORQUING
Phase I & II are maintained.
An 0.018” S.S. wire with bite opening bends is placed in the gingival slots.
Tandem nickel – titanium arch wire are placed into edge wise slots for
uprighting and torque.
Wires can be 0.016” NiTi.
0.018 square NiTi.
Class II elastics are continued 4 ounceswww.indiandentalacademy.com
31. PHASE IV DETAILING AND FINISHING.
1. Ideal arch wires are used in edge wise slots.
- 0.016” x 0.22” or 0.018” x 0.025” are used.
Arch wires should be relatively straight if the bracket placement and
tooth offset bends in the arch wire usually are necessary to over come
bracket height discrepancies.
A reverse curve of spee may be used for optimum leveling of the
occlusal plane in the mandibular arch.
TREATMENT CONSIDERATIONS
Principles to the consider in CAT
Gingival slot is used when maximum movement is desired.
Edge wise slot is used when rigidity and limited movement are desired.
CAT can be adopted to treat
1.Single arch cases.
2.Unilateral problems.
3.Mid line discrepancies.
4.Class III Mal occlusion.www.indiandentalacademy.com
33. CAT
Treatment mechanics for different treatment plan.
Mechanics : The conditions are modified to accommodate the needs of each
case of varying the anchorage differential.
Example : Treatment in mid line discrepancy. Determine which of the dental
arches (or both) does not coincide with the facial mid line.
If the dental midline is off centre is only one jaw – then the edge wise
resistance increased in the co-ordinated and central arch; tipping
movements are used to directionally tip the teeth in the dental arch that is
off center.
If both the mid lines are not coincident with the facial centre line, then both
arch wires are placed in the gingival slots so that all teeth can tip easily in
both arches that is off center.
They are tipped with opposing class II and Class III elastics until the
midlines
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34. Then use 0.018” S.S arches are placed in the gingival slot.
Flexible NiTi wires are placed in the edge wise slot as tandem to produce
the uprighting and root positioning.
So principle is when maximum movement of teeth is desired, the gingival
tipping slot is used.
When rigidity and limited movements are desired, use edge wise slot.
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35. DISTALIZATION IN NON EXTRACTION CASES
•Can be done without extra oral appliances
•Differential resistance anchorage is used in either gingival or straight wire
slot, depending on which teeth are selected as anchor teeth or movement
teeth.
•In case of minimal crowding.
•Treatment is started with arch wires in the gingival round tubes and in the
gingival bracket slots.
•The mechanical effect of the anchor bend and elastic forces on the single
point contact of the arch wire in the gingival slot tends to automatically
move the canines and incisors digitally , creating space for incisor
alignment.
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36. •If light wire slots with single point contacts are used in initial non
extraction mechanics, spaces are obtained for alignment of incisors.
•The angular effect of the anchor bend on the one point contact distalize
canine teeth automatically.
•Bite opening with 1 ½ to 3 ouches of elastic force in conjunction with
proper intrusive mechanics on incisors and extraction of molars.
•Straight wire finally gives good esthetics and occlusal symmetry.
•When there is adequate space for the incisors, arch wires are engaged in
the edge wise slots to establish more anterior anchorage resistance.
•Maxillary arch used anterior edge wise slots are used.
•Mandibular arches, all edge wise slots are used.
•This arrangement established complete anchorage resistance in the entire
lower arch and maximum anterior resistance in the maxillary incisor area.
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37. Auxillaries such as coils, jigs or elastics are then used to distalize the
maxillary molars by tipping them distally with wires in the large, round light
wire tubes.
Class II Elastics of 2 to 3 ounces are used to augument the anterior
anchorage force acting against the coils and jigs to provide distalization of
the molars.
Once the molars have been distalized to their proper position. These are held
in this position with crimped stops, and the canines and premolars are
tipped
distally in the loose fitting gingival slots. When all the posterior teeth have
been properly positioned, the anterior teeth are tipped into position.
Final uprighting and alignment are done with edge wise wires.
No need to use head gear therapy for distalizing the teeth as there is
establishment of complete anchorage resistance in one arch and free tipping
in the other arch.
If a skeletal disharmony is evident and orthopedic force is indicated, head
gear forces can be used with the appliance by means of special head gear
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38. ADVANTAGES OR FAVORABLE FINDINGS IN
COMBINATION SYSTEMS
Time factor
Stage III can be altered because of the shortening of the usual uprighting
periods by finishing and uprighting and torque in the rectangular slot.
In class I extraction cases – those stages II closure may be minimal and
uprighting of canines, stage III may be completely eliminated and only
rectangular finishing may be needed.
It is often possible to enter the rectangular slot with the main wire very early in
the non extraction cases and to control most of the uprighting and torque with
only the straight wire type and angulated and torqued slot.
Transfer the cases : It is easies to transfer the cases to some other clinician,
who had experience with this technique. In their system orthodontic can switch
to a slot he feels best able to control.www.indiandentalacademy.com
39. Clinical use of the combined Begg and straight wire type of appliances have
been very gratifying
CAT has good potential for clinical orthodontics. Much can be expected by
new designs and combinations as the idea progresses.
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40. CONCLUSIONS
CAT in our practice has been gratifying.
Approach with modified brackets has been efficient, effective, and
esthetically pleasing, satisfactory to the patient.
CAT has provided optimum anchorage control and tooth movement in
any given situation.
Finally: What we think we know today shatters the errors and blunders
of yesterday and is tomorrow discarded as worthless.
So, we go from larger mistake to smaller mistakes, so long as we do
not loose courage.
This is true of all therapy no method is final.
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41. • References
1. William J. Thompson. Combination
anchorage technique: An update of
current mechanics. Am J Orthod Dentofac
Orthop: 1988: 5: (363 - 379).
2. William J. Thompson. Begg and straight
wire: A combination approach to
treatment. Am J Orthod Dentofac Orthop:
1981: 6: (591 - 609).
3. JAMES L. CANNON. Dual-Flex
Archwires. J Clinc Orthod: 1984: 9: (648 -
649). www.indiandentalacademy.com